Kylie Jenner, once a major Snapchat celebrity, has now largely abandoned the platform.
Photograph: James Gourley/BEI/Rex/Shutterstock

More than $1bn was wiped off Snap Inc’s market value on Thursday, in one of the company’s worst trading days since it went public last year – and the rout was led by a bored tweet from a member of the Kardashian clan.

Kylie Jenner, one of the first wave of celebrities whose fame grew primarily on Snapchat over other social media firms, shared her disappointment with the app on Twitter late on Wednesday: “sooo does anyone else not open Snapchat anymore? Or is it just me ... ugh this is so sad,” she said. “[S]till love you tho snap ... my first love”.

Kylie Jenner (@KylieJenner)

sooo does anyone else not open Snapchat anymore? Or is it just me... ugh this is so sad.

Jenner’s tweet, combined with growing fears on the part of investors that a long-awaited usability-focused redesign may not solve Snapchat’s user growth issues, sparked a plunge in the company’s stock, which fell 6% over the course of Thursday, clearing $1.3bn from its market capitalisation.

The redesign of the app saw Snapchat move away from its previous split between “messages” and “stories”, the social media convention invented by the company but usurped by Facebook’s Instagram. Now, Snapchat focuses attention on the division between friends and publishers, allowing it to more easily promote professional (and paid-for) content, while grouping everything from actual acquaintances in one place.

But it isn’t just Snapchat’s celebrity users and investors who have expressed frustration with the new direction the app has taken. A petition from more than 1.2 million users begged the company to reconsider its redesign, eventually forcing a somewhat dismissive response from Snap Inc itself.

“We completely understand the new Snapchat has felt uncomfortable for many,” the company said. However, it added, “this new foundation is just the beginning and we will always listen closely to find new ways to make the service better for everyone”.

The petition’s core complaint is that the new update “has not made the app easier to use, but has in fact made many features more difficult … Many ‘new features’ are useless or defeat the original purposes Snapchat has had for the past years.”

In the run up to the redesign, the company’s co-founder and chief executive Evan Spiegel promised it would satisfy concerns (particularly among investors) that Snapchat was too difficult to use. But he also hoped that the redesign could help fix some common problems faced by all social media apps, he told the Guardian before the launch.

“For a very long time, we have been trying to clarify, or at least distinguish, the difference between friends and publishers,” Spiegel said in November. “Like, on the Stories page, do you show friends or publishers first? Because our service was really built on this idea of helping friends communicate, we chose friends – and ultimately what that meant is that all of this awesome publisher content was all the way down at the bottom.”

Despite the criticism, Spiegel remains characteristically bolshy about the new design, telling a conference in San Francisco that “some of the complaints we’re seeing reinforce the philosophy.

“One of the complaints we got was, ‘wow I used to feel like this celebrity was my friend and now they don’t feel like my friend anymore’. And we’re like: ‘Exactly. They’re not your friend.’ So for us, even some of the frustrations we’re seeing really validate those changes. And it’ll take time for people to adjust.”